Biochemical and Structural Characterization of a Five-domain GH115-Glucuronidase from the Marine Bacterium Saccharophagus degradans 2-40(T)
Journal article, 2016
Glucuronic acid (GlcAp) and/or methylglucuronic acid (MeGlcAp) decorate the major forms of xylan in hardwood and coniferous softwoods as well as many cereal grains. Accordingly, the complete utilization of glucuronoxylans or conversion to sugar precursors requires the action of main chain xylanases as well as -glucuronidases that release the - (12)-linked (Me)GlcAp side groups. Herein, a family GH115 enzymefrom the marine bacterium Saccharophagus degradans 2-40(T), SdeAgu115A, demonstrated activity toward glucuronoxylan and oligomers thereof with preference toward MeGlcAp linked to internal xylopyranosyl residues. Unique biochemical characteristics of NaCl activation were also observed. The crystal structure of SdeAgu115A revealed a five-domain architecture, with an additional insertion C+ domain that had significant impact on the domain arrangement of SdeAgu115A monomer and its dimerization. The participation of domain C+ in substrate binding was supported by reduced substrate inhibition upon introducing W773A, W689A, and F696A substitutions within this domain. In addition to Asp-335, the catalytic essentiality of Glu-216 was revealed by site-specific mutagenesis. A primary sequence analysis suggested that the SdeAgu115A architecture is shared by more than half of GH115 members, thus defining a distinct archetype for GH115 enzymes.
carbohydrate
polysaccharides
GH115-glucuronidase
inverting character
thermotoga-maritima msb8
catalytic apparatus
1992
carbohydrate degradation
v207
p176
ruiter ga
family gh115
modification
Biochemistry & Molecular Biology
crystal-structures
analytical biochemistry
crystal structure
alpha-glucuronidase
xylan
protein domain
enzyme domain composition
schizophyllum-commune
enzyme structure
enzyme catalysis
plant-cell wall
density
Author
W. J. Wang
R. Y. Yan
B. P. Nocek
T. V. Vuong
R. Di Leo
X. H. Xu
H. Cui
Paul Gatenholm
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Guillermo Toriz Gonzalez
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
M. Tenkanen
A. Savchenko
E. R. Master
Journal of Biological Chemistry
0021-9258 (ISSN) 1083-351X (eISSN)
Vol. 291 27 14120-14133Subject Categories (SSIF 2011)
Biochemistry and Molecular Biology
DOI
10.1074/jbc.M115.702944
PubMed
27129264